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author | BurdetteLamar <burdettelamar@yahoo.com> | 2020-05-22 15:40:01 -0500 |
---|---|---|
committer | Samuel Williams <samuel.williams@oriontransfer.co.nz> | 2020-05-23 12:36:42 +1200 |
commit | da484c3187523a7cf35130f64783b431a61004a6 (patch) | |
tree | e1eb33ead1ad8076def0aae7c1a7c0c3aaa56ba9 | |
parent | f8647343edf917142bea63f5e1c9f867674d1e5f (diff) | |
download | ruby-da484c3187523a7cf35130f64783b431a61004a6.tar.gz |
Enhanced Rdoc for Hash
-rw-r--r-- | hash.c | 141 |
1 files changed, 104 insertions, 37 deletions
@@ -2504,20 +2504,43 @@ rb_hash_delete(VALUE hash, VALUE key) /* * call-seq: - * hsh.delete(key) -> value - * hsh.delete(key) {| key | block } -> value + * hash.delete(key) -> value or nil + * hash.delete(key) { |key| ... } -<value * - * Deletes the key-value pair and returns the value from <i>hsh</i> whose - * key is equal to <i>key</i>. If the key is not found, it returns - * <em>nil</em>. If the optional code block is given and the - * key is not found, pass in the key and return the result of - * <i>block</i>. + * Deletes the entry for the given +key+ + * and returns its associated value. * - * h = { "a" => 100, "b" => 200 } - * h.delete("a") #=> 100 - * h.delete("z") #=> nil - * h.delete("z") { |el| "#{el} not found" } #=> "z not found" + * --- + * + * If no block is given and +key+ is found, deletes the entry and returns the associated value: + * h = {foo: 0, bar: 1, baz: 2} + * h.delete(:bar) # => 1 + * h # => {:foo=>0, :baz=>2} + * + * If no block given and +key+ is not found, returns +nil+: + * h = {foo: 0, bar: 1, baz: 2} + * h.delete(:nosuch) # => nil + * h # => {:foo=>0, :bar=>1, :baz=>2} + * + * If a block is given and +key+ is found, ignores the block, + * deletes the entry, and returns the associated value: + * h = {foo: 0, bar: 1, baz: 2} + * h.delete(:baz) { |key| fail 'Will never happen'} # => 2 + * h # => {:foo=>0, :bar=>1} * + * If a block is given and +key+ is not found, + * calls the block and returns the block's return value: + * h = {foo: 0, bar: 1, baz: 2} + * h.delete(:nosuch) { |key| "Key #{key} not found" } # => "Key nosuch not found" + * h # => {:foo=>0, :bar=>1, :baz=>2} + * + * --- + * + * Raises an exception if +key+ is invalid + * (see {Invalid Hash Keys}[#class-Hash-label-Invalid+Hash+Keys]): + * h = {foo: 0, bar: 1, baz: 2} + * # Raises NoMethodError (undefined method `hash' for #<BasicObject:>): + * h.delete(BasicObject.new) */ static VALUE @@ -2558,15 +2581,19 @@ shift_i_safe(VALUE key, VALUE value, VALUE arg) /* * call-seq: - * hsh.shift -> anArray or obj + * hash.shift -> [key, value] or default_value * - * Removes a key-value pair from <i>hsh</i> and returns it as the - * two-item array <code>[</code> <i>key, value</i> <code>]</code>, or - * the hash's default value if the hash is empty. + * Removes the first hash entry + * (see {Entry Order}[#class-Hash-label-Entry+Order]); + * returns a 2-element Array containing the removed key and value: + * h = {foo: 0, bar: 1, baz: 2} + * h.shift # => [:foo, 0] + * h # => {:bar=>1, :baz=>2} * - * h = { 1 => "a", 2 => "b", 3 => "c" } - * h.shift #=> [1, "a"] - * h #=> {2=>"b", 3=>"c"} + * Returns the default value if the hash is empty + * (see {Default Values}[#class-Hash-label-Default+Values]): + * h = {} + * h.shift # => nil */ static VALUE @@ -2625,17 +2652,30 @@ hash_enum_size(VALUE hash, VALUE args, VALUE eobj) /* * call-seq: - * hsh.delete_if {| key, value | block } -> hsh - * hsh.delete_if -> an_enumerator + * hash.delete_if {|key, value| ... } -> self + * hash.delete_if -> new_enumerator * - * Deletes every key-value pair from <i>hsh</i> for which <i>block</i> - * evaluates to <code>true</code>. + * If a block given, calls the block with each key-value pair; + * deletes each entry for which the block returns a truthy value; + * returns +self+: + * h = {foo: 0, bar: 1, baz: 2} + * h1 = h.delete_if { |key, value| value > 0 } + * h1 # => {:foo=>0} + * h1.equal?(h) # => true # Identity check * - * If no block is given, an enumerator is returned instead. + * If no block given, returns a new \Enumerator: + * h = {foo: 0, bar: 1, baz: 2} + * e = h.delete_if # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:delete_if> + * h1 = e.each { |key, value| value > 0 } + * h1 # => {:foo=>0} + * h1.equal?(h) # => true # Identity check * - * h = { "a" => 100, "b" => 200, "c" => 300 } - * h.delete_if {|key, value| key >= "b" } #=> {"a"=>100} + * ---- * + * Raises an exception if the block attempts to add a new key: + * h = {foo: 0, bar: 1, baz: 2} + * # Raises RuntimeError (can't add a new key into hash during iteration): + * h.delete_if { |key, value| h[:new_key] = 3 } */ VALUE @@ -2651,11 +2691,34 @@ rb_hash_delete_if(VALUE hash) /* * call-seq: - * hsh.reject! {| key, value | block } -> hsh or nil - * hsh.reject! -> an_enumerator + * hash.reject! {|key, value| ... } -> self or nil + * hash.reject! -> new_enumerator + * + * Returns +self+, whose remaining entries are those + * for which the block returns +false+ or +nil+: + * h = {foo: 0, bar: 1, baz: 2} + * h1 = h.reject! {|key, value| value < 2 } + * h1 # => {:baz=>2} + * h1.equal?(h) # => true # Identity check + * + * Returns +nil+ if no entries are removed: + * h = {foo: 0, bar: 1, baz: 2} + * h.reject! {|key, value| value > 2 } # => nil + * h # => {:foo=>0, :bar=>1, :baz=>2} * - * Equivalent to Hash#delete_if, but returns - * <code>nil</code> if no changes were made. + * Returns a new \Enumerator if no block given: + * h = {foo: 0, bar: 1, baz: 2} + * e = h.reject! # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:reject!> + * h1 = e.each {|key, value| key.start_with?('b') } + * h1 # => {:foo=>0} + * h1.equal?(h) # => true # Identity check + * + * --- + * + * Raises an exception if the block attempts to add a new key: + * h = {foo: 0, bar: 1, baz: 2} + * # Raises RuntimeError (can't add a new key into hash during iteration): + * h.reject! { |key, value| h[:new_Key] = 3 } */ VALUE @@ -2683,16 +2746,20 @@ reject_i(VALUE key, VALUE value, VALUE result) /* * call-seq: - * hsh.reject {|key, value| block} -> a_hash - * hsh.reject -> an_enumerator + * hash.reject {|key, value| ... } -> new_hash + * hash.reject -> new_enumerator * - * Returns a new hash consisting of entries for which the block returns false. - * - * If no block is given, an enumerator is returned instead. + * Returns a new \Hash object whose entries are all those + * from +self+ for which the block returns +false+ or +nil+: + * h = {foo: 0, bar: 1, baz: 2} + * h1 = h.reject {|key, value| key.start_with?('b') } + * h1 # => {:foo=>0} * - * h = { "a" => 100, "b" => 200, "c" => 300 } - * h.reject {|k,v| k < "b"} #=> {"b" => 200, "c" => 300} - * h.reject {|k,v| v > 100} #=> {"a" => 100} + * Returns a new Enumerator if no block given: + * h = {foo: 0, bar: 1, baz: 2} + * e = h.reject # => #<Enumerator: {:foo=>0, :bar=>1, :baz=>2}:reject> + * h1 = e.each {|key, value| key.start_with?('b') } + * h1 # => {:foo=>0} */ VALUE |